Der evolutionäre Ursprung der Jasmonat-responsiven Signaltransduktion und der Jasmonat Biosynthese
Biochemie und Biophysik der Pflanzen
Genetik und Genomik der Pflanzen
Zusammenfassung der Projektergebnisse
The wound response of land plants involves the accumulation of oxylipins such as jasmonic acid (JA) or its biosynthetic precursors 12-oxo-phytodienoic acid (OPDA) and dinor-OPDA (dn-OPDA). In angiosperms, the evolutionary conserved receptor CORONATINE INSENSITIVE 1 (COI1) is activated by the JA conjugate jasmonoyl-isoleucine (JA-Ile), while dn-OPDA is the COI1 ligand in all bryophyte species tested so far. We have found that only trace amounts of JA, JA-Ile or dn-OPDA accumulate upon wounding in four species from different sub-orders of the polypod ferns (Polypodiales), while the tree fern Alsophila salvinii and the horsetail Equisetum scirpoides resemble angiosperms with respect to the quantity of JA and JA-Ile accumulation. Non-targeted metabolite fingerprinting led to the identification of a woundinduced unknown oylipin (UNO210) that is conserved in different suborders of the Polypodiales and absent in all species with efficient JA accumulation. UNO210 might serve as an alternative COI1 ligand. In yeast two-hybrid and co-immunoprecipitation experiments polypod COI1 proteins and JASMONATE ZIM-domain (JAZ) did not interact in the presence of JA-Ile or coronatine, suggesting a low binding activity of polypod COI1 proteins towards these ligands. Still, individual polypod fern COI1 proteins are activated by JA-Ile in a functional assay in Arabiopsis protoplasts, although less efficiently than Arabidopsis COI1. The notion that polypod fern COI1 proteins can respond to JA is supported by transcriptome analysis. Since salt-treated Arabidopsis roots respond with the activation of the JA signaling pathway at very low JA-Ile levels, we propose that polypod ferns do so as well. It remains to be elucidated whether COI1 proteins can be post-translationally modified to allow ligand binding at very low levels of the hormone.
Projektbezogene Publikationen (Auswahl)
-
(2019). Cells 8.1532
Li, N., Uhrig, J.F., Thurow, C., Huang, L.J., and Gatz, C.
-
(2020). Plants 9
Thurow, C., Krischke, M., Mueller, M.J., and Gatz, C.
